/* Spring Core — design system (companion to Java Core, Service Core, Unix Core) */

body.spring-core {
  --sp-bg: #1e1e2e;
  --sp-bg-elevated: #252536;
  --sp-bg-panel: #2a2a3d;
  --sp-border: #3d3d52;
  --sp-border-bright: #52526a;
  --sp-text: #ececf1;
  --sp-text-muted: #a8a8b8;
  --sp-text-dim: #6e6e82;
  --sp-accent: #6db33f;
  --sp-accent-dim: rgba(109, 179, 63, 0.14);
  --sp-accent-glow: rgba(109, 179, 63, 0.35);
  --sp-leaf: #5a9e34;
  --sp-cyan: #56cfe1;
  --sp-cyan-dim: rgba(86, 207, 225, 0.12);
  --sp-green: #6db33f;
  --sp-green-dim: rgba(109, 179, 63, 0.12);
  --sp-red: #ef5350;
  --sp-red-dim: rgba(239, 83, 80, 0.12);
  --sp-purple: #9b7ede;
  --sp-purple-dim: rgba(155, 126, 222, 0.12);
  --sp-amber: #e8b84a;
  --sp-amber-dim: rgba(232, 184, 74, 0.12);
  --sp-grey: #8b949e;
  --sp-grey-dim: rgba(139, 148, 158, 0.12);
  --sp-font-body: "Inter", system-ui, -apple-system, sans-serif;
  --sp-font-mono: "JetBrains Mono", ui-monospace, "Cascadia Code", monospace;
  --sp-font-display: "Inter", system-ui, -apple-system, sans-serif;
  --sp-radius: 8px;
  --sp-radius-lg: 12px;
  --sp-shadow: 0 8px 32px rgba(0, 0, 0, 0.45);
  --sp-max-width: var(--sp-content-width);
  --sp-nav-height: 3.5rem;
  --sp-transition: 0.15s ease;
  --sp-sidebar-width: 220px;

  /* Personas */
  --persona-junior: #56cfe1;
  --persona-junior-bg: rgba(86, 207, 225, 0.12);
  --persona-mid: #6db33f;
  --persona-mid-bg: rgba(109, 179, 63, 0.12);
  --persona-senior: #9b7ede;
  --persona-senior-bg: rgba(155, 126, 222, 0.12);

  /* Callout accents */
  --callout-pitfall: var(--sp-red);
  --callout-tip: var(--sp-green);
  --callout-hood: var(--sp-cyan);
  --callout-interview: var(--sp-amber);
  --callout-realworld: var(--sp-purple);
  --callout-version: var(--sp-grey);

  /* Typography — Inter reading scale (see assets/core-typography.css) */
  --sp-font-h1: clamp(1.75rem, 1.5rem + 1.5vw, 2.5rem);
  --sp-font-h2: clamp(1.375rem, 1.2rem + 0.9vw, 1.875rem);
  --sp-font-h3: clamp(1.125rem, 1rem + 0.55vw, 1.5rem);
  --sp-font-size: clamp(1rem, 0.97rem + 0.2vw, 1.125rem);
  --sp-font-size-read: var(--sp-font-size);
  --sp-font-size-small: 0.875rem;
  --sp-font-size-table: var(--sp-font-size-small);
  --sp-font-size-code: clamp(0.8125rem, 0.78rem + 0.15vw, 0.9375rem);
  --sp-line-height: 1.75;
  --sp-line-height-read: 1.75;
  --sp-content-width: min(800px, 92vw);
  --sp-doc-width: min(800px, 92vw);
}

html[data-hp-theme="light"] body.spring-core {
  --sp-bg: #f2f4f0;
  --sp-bg-elevated: #ffffff;
  --sp-bg-panel: #e8ece4;
  --sp-border: #c5cec0;
  --sp-border-bright: #9aab94;
  --sp-text: #1e1e2e;
  --sp-text-muted: #4a5568;
  --sp-text-dim: #718096;
  --sp-accent: #4a8f2a;
  --sp-accent-dim: rgba(74, 143, 42, 0.1);
  --sp-accent-glow: rgba(74, 143, 42, 0.2);
  --sp-shadow: 0 8px 24px rgba(30, 30, 46, 0.08);
  --persona-junior: #0277bd;
  --persona-junior-bg: rgba(2, 119, 189, 0.1);
  --persona-mid: #4a8f2a;
  --persona-mid-bg: rgba(74, 143, 42, 0.1);
  --persona-senior: #7b1fa2;
  --persona-senior-bg: rgba(123, 31, 162, 0.1);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body.spring-core {
  margin: 0;
  min-height: 100vh;
  background: var(--sp-bg) !important;
  color: var(--sp-text);
  font-family: var(--sp-font-body);
  font-size: var(--sp-font-size);
  line-height: var(--sp-line-height);
  -webkit-font-smoothing: antialiased;
}

/* Chapter pages — reading layout handled in assets/core-typography.css */

body.spring-core::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  opacity: 0.4;
  background-image:
    radial-gradient(circle at 15% 12%, rgba(109, 179, 63, 0.1) 0, transparent 42%),
    radial-gradient(circle at 85% 78%, rgba(86, 207, 225, 0.06) 0, transparent 38%),
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='80' height='80' viewBox='0 0 80 80'%3E%3Cpath d='M40 8c-8 12-8 24 0 36 8-12 8-24 0-36z' fill='%236db33f' fill-opacity='0.04'/%3E%3C/svg%3E");
  background-size: auto, auto, 80px 80px;
  mask-image: radial-gradient(ellipse 90% 80% at 50% 20%, #000 15%, transparent 75%);
}

body.spring-core .sp-main,
body.spring-core .sp-topbar,
body.spring-core .sp-footer {
  position: relative;
  z-index: 1;
}

html[data-hp-theme="light"] body.spring-core::before {
  opacity: 0.25;
}

a {
  color: var(--sp-cyan);
  text-decoration: none;
  transition: color var(--sp-transition);
}

a:hover {
  color: var(--sp-accent);
  text-decoration: underline;
}

a:focus-visible {
  outline: 2px solid var(--sp-accent);
  outline-offset: 2px;
  border-radius: 2px;
}

img {
  max-width: 100%;
  height: auto;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ── Top bar (aligned with site-topbar + reading-room compact scroll) ── */

html:has(body.spring-core) {
  --sp-topbar-compact: 0;
}

body.spring-core {
  --sp-compact-inset: clamp(14px, 2.8vw, 24px);
}

body.spring-core .sp-topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: color-mix(
    in srgb,
    var(--sp-chrome-bg, var(--sp-bg)) calc((1 - var(--sp-topbar-compact, 0)) * 100%),
    transparent
  ) !important;
  border-bottom: 1px solid
    color-mix(
      in srgb,
      var(--sp-chrome-border, var(--sp-border)) calc((1 - var(--sp-topbar-compact, 0)) * 100%),
      transparent
    ) !important;
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
  transition:
    min-height 0.35s ease,
    box-shadow 0.35s ease,
    background 0.35s ease,
    border-color 0.35s ease;
}

html[data-hp-theme="light"] body.spring-core {
  --sp-chrome-bg: var(--hp-bg, #f5f2eb);
  --sp-chrome-border: var(--hp-border, rgba(26, 22, 18, 0.1));
  --sp-chrome-text: var(--hp-text, #1a1612);
  --sp-chrome-muted: var(--hp-muted, #5c554c);
  --sp-chrome-accent: var(--hp-accent, #1a6b4a);
}

html[data-hp-theme="dark"] body.spring-core,
html:not([data-hp-theme]) body.spring-core {
  --sp-chrome-bg: #090c14;
  --sp-chrome-border: rgba(255, 255, 255, 0.08);
  --sp-chrome-text: #e8eaef;
  --sp-chrome-muted: #8b949e;
  --sp-chrome-accent: #5cefb8;
}

body.spring-core .sp-topbar .site-topbar__inner {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  grid-template-areas: "brand main actions";
  align-items: center;
  gap: 12px 20px;
  max-width: var(--site-topbar-max, 1280px);
  margin: 0 auto;
  min-height: var(--sp-nav-height);
  padding: 14px var(--site-topbar-pad-x, clamp(20px, 4vw, 40px));
  padding-left: calc(
    var(--site-topbar-pad-x, clamp(20px, 4vw, 40px)) * (1 - var(--sp-topbar-compact, 0)) +
      (env(safe-area-inset-left, 0px) + var(--sp-compact-inset)) * var(--sp-topbar-compact, 0)
  );
  transition:
    max-width 0.42s cubic-bezier(0.4, 0, 0.2, 1),
    margin 0.42s cubic-bezier(0.4, 0, 0.2, 1),
    padding 0.42s cubic-bezier(0.4, 0, 0.2, 1),
    gap 0.35s ease,
    min-height 0.35s ease;
}

body.spring-core .sp-topbar .site-topbar__inner > :not(.site-brand) {
  opacity: calc(1 - var(--sp-topbar-compact, 0));
  overflow: hidden;
  transition: opacity 0.35s ease;
}

body.spring-core.sp-topbar--compact .sp-topbar .site-topbar__inner > :not(.site-brand) {
  pointer-events: none;
}

body.spring-core.sp-topbar--compact {
  --site-topbar-sticky-offset: 3.5rem;
}

body.spring-core.sp-topbar--compact .sp-topbar {
  min-height: var(--site-topbar-sticky-offset);
  box-shadow: none;
}

body.spring-core.sp-topbar--compact .sp-topbar .site-topbar__inner {
  width: 100%;
  max-width: none;
  margin-inline: 0;
  gap: calc(12px * (1 - var(--sp-topbar-compact, 1)));
  min-height: 44px;
  padding-top: max(8px, env(safe-area-inset-top, 0px));
  padding-bottom: 8px;
  padding-right: var(--site-topbar-pad-x, clamp(20px, 4vw, 40px));
}

body.spring-core.sp-topbar--compact .sp-topbar .site-topbar__inner > :not(.site-brand) {
  width: 0;
  min-width: 0;
  max-width: 0;
  margin: 0;
  padding: 0;
  border: 0;
  visibility: hidden;
}

body.spring-core.sp-topbar--compact .sp-topbar .site-brand {
  grid-template-columns: 40px minmax(0, 1fr);
  column-gap: clamp(6px, 1.6vw, 10px);
  margin: 0;
  padding: 0;
  font-size: clamp(0.82rem, 2.6vw, 0.96rem);
  max-width: min(100%, 12.5rem);
}

body.spring-core.sp-topbar--compact .sp-topbar .site-brand > .site-brand__mark {
  width: 40px;
  height: 40px;
}

body.spring-core.sp-topbar--compact .sp-topbar .site-brand__mark {
  filter: drop-shadow(0 1px 3px rgba(0, 0, 0, 0.2));
}

body.spring-core .sp-topbar .site-brand {
  grid-area: brand;
  justify-self: start;
  font-family: "Inter", system-ui, sans-serif;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--sp-chrome-text, var(--sp-text));
  text-decoration: none;
  transition: column-gap 0.35s ease, color var(--sp-transition);
}

body.spring-core .sp-topbar .site-brand:hover {
  color: var(--sp-chrome-accent, var(--sp-accent));
  text-decoration: none;
}

body.spring-core .sp-topbar .site-brand > span {
  overflow: hidden;
  white-space: nowrap;
  min-width: 0;
}

body.spring-core .sp-topbar .site-brand__tld {
  color: var(--sp-chrome-accent, var(--sp-accent));
}

body.spring-core .sp-topbar .hp-topbar__actions,
body.spring-core .sp-topbar .site-topbar__actions {
  grid-area: actions;
  justify-self: end;
}

body.spring-core .sp-topbar a {
  text-decoration: none;
}

body.spring-core .sp-topbar a:hover {
  text-decoration: none;
}

@media (prefers-reduced-motion: reduce) {
  body.spring-core .sp-topbar,
  body.spring-core .sp-topbar .site-topbar__inner,
  body.spring-core .sp-topbar .site-topbar__inner > :not(.site-brand),
  body.spring-core .sp-topbar .site-brand {
    transition: none;
  }
}

/* ── Main layout ── */

.sp-main {
  max-width: var(--sp-max-width);
  margin: 0 auto;
  padding: clamp(24px, 5vw, 48px) clamp(16px, 4vw, 32px) 64px;
}

.sp-breadcrumb {
  margin-bottom: 24px;
  font-size: 12px;
  color: var(--sp-text-muted);
}

.sp-breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.sp-breadcrumb li:not(:last-child)::after {
  content: "/";
  margin-left: 6px;
  color: var(--sp-text-dim);
}

.sp-breadcrumb [aria-current="page"] {
  color: var(--sp-accent);
}

.sp-mobile-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--sp-border);
}

.sp-mobile-nav a {
  padding: 4px 10px;
  font-size: 11px;
  font-family: var(--sp-font-mono);
  border: 1px solid var(--sp-border);
  border-radius: 999px;
  color: var(--sp-text-muted);
  text-decoration: none;
}

.sp-mobile-nav a:hover {
  border-color: var(--sp-accent);
  color: var(--sp-accent);
  text-decoration: none;
}

@media (min-width: 900px) {
  .sp-mobile-nav {
    display: none;
  }
}

/* ── Hero ── */

.sp-hero {
  margin-bottom: 56px;
  max-width: 52rem;
}

.sp-hero__kicker {
  margin: 0 0 12px;
  font-family: var(--sp-font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--sp-accent);
}

.sp-hero__title {
  margin: 0 0 16px;
  font-family: var(--sp-font-display);
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
}

.sp-hero__title span {
  color: var(--sp-accent);
}

.sp-hero__lede {
  margin: 0 0 24px;
  font-size: 16px;
  line-height: 1.75;
  color: var(--sp-text-muted);
  max-width: 52ch;
}

.sp-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.sp-hero--landing {
  max-width: none;
  margin-bottom: 48px;
}

.sp-hero--landing .sp-hero__why {
  margin-top: 40px;
  padding-top: 32px;
  border-top: 1px solid var(--sp-border);
}

.sp-hero--landing .sp-hero__why-title {
  margin: 0 0 8px;
  font-size: clamp(1.2rem, 2.5vw, 1.45rem);
  font-weight: 700;
}

.sp-hero--landing .sp-hero__why-lede {
  margin: 0 0 20px;
  color: var(--sp-text-muted);
  max-width: 65ch;
  line-height: 1.7;
}

.sp-hub-anchors {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--sp-border);
}

.sp-hub-anchors a {
  padding: 6px 12px;
  border: 1px solid var(--sp-border);
  border-radius: 999px;
  font-family: var(--sp-font-mono);
  font-size: 11px;
  color: var(--sp-text-muted);
  text-decoration: none;
  transition: border-color var(--sp-transition), color var(--sp-transition);
}

.sp-hub-anchors a:hover {
  border-color: var(--sp-accent);
  color: var(--sp-accent);
  text-decoration: none;
}

.sp-jvm-stack {
  display: grid;
  gap: 12px;
  margin: 20px 0;
}

@media (min-width: 720px) {
  .sp-jvm-stack {
    grid-template-columns: repeat(3, 1fr);
  }
}

.sp-jvm-stack__card {
  padding: 16px;
  border: 1px solid var(--sp-border);
  border-radius: var(--sp-radius-lg);
  background: var(--sp-bg-elevated);
}

.sp-jvm-stack__card h4 {
  margin: 0 0 8px;
  font-family: var(--sp-font-mono);
  font-size: 13px;
  font-weight: 600;
  color: var(--sp-accent);
}

.sp-jvm-stack__card p {
  margin: 0;
  font-size: 13px;
  color: var(--sp-text-muted);
  line-height: 1.6;
}

.sp-learning-path {
  margin: 0 0 20px;
  padding: 14px 16px;
  border-left: 3px solid var(--sp-accent);
  border-radius: 0 var(--sp-radius) var(--sp-radius) 0;
  background: var(--sp-accent-dim);
  font-size: 13px;
  color: var(--sp-text-muted);
  line-height: 1.65;
}

.sp-learning-path strong {
  color: var(--sp-text);
}

.sp-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border-radius: var(--sp-radius);
  font-family: var(--sp-font-mono);
  font-size: 13px;
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  transition: background var(--sp-transition), border-color var(--sp-transition), color var(--sp-transition);
}

body.spring-core a.sp-btn,
body.spring-core a.sp-btn:hover {
  border-bottom: none;
}

body.spring-core a.sp-btn--primary {
  background: var(--sp-accent-dim);
  border-color: var(--sp-accent);
  color: var(--sp-accent);
}

body.spring-core a.sp-btn--primary:hover {
  background: var(--sp-accent);
  color: #1a1a2e;
  text-decoration: none;
}

body.spring-core a.sp-btn--ghost {
  background: transparent;
  border-color: var(--sp-border);
  color: var(--sp-text-muted);
}

body.spring-core a.sp-btn--ghost:hover {
  border-color: var(--sp-border-bright);
  color: var(--sp-text);
  text-decoration: none;
}

/* ── Search & persona filter (hub + content pages) ── */

.sp-toolbar {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 32px;
  padding: 16px;
  border: 1px solid var(--sp-border);
  border-radius: var(--sp-radius-lg);
  background: var(--sp-bg-elevated);
}

@media (min-width: 640px) {
  .sp-toolbar {
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
  }
}

.sp-search {
  flex: 1;
  min-width: 200px;
  position: relative;
}

.sp-search__input {
  width: 100%;
  padding: 10px 14px 10px 36px;
  border: 1px solid var(--sp-border);
  border-radius: var(--sp-radius);
  background: var(--sp-bg);
  color: var(--sp-text);
  font-family: var(--sp-font-mono);
  font-size: 13px;
  outline: none;
}

.sp-search__input:focus {
  border-color: var(--sp-accent);
  box-shadow: 0 0 0 2px var(--sp-accent-dim);
}

.sp-search__input::placeholder {
  color: var(--sp-text-dim);
}

.sp-search__icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 14px;
  color: var(--sp-text-dim);
  pointer-events: none;
}

.sp-search__results {
  margin: 8px 0 0;
  font-size: 12px;
  color: var(--sp-text-muted);
}

.sp-persona-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.sp-persona-filter__btn {
  appearance: none;
  padding: 6px 12px;
  border: 1px solid var(--sp-border);
  border-radius: 999px;
  background: transparent;
  color: var(--sp-text-muted);
  font-family: var(--sp-font-mono);
  font-size: 11px;
  font-weight: 500;
  cursor: pointer;
  transition: border-color var(--sp-transition), background var(--sp-transition), color var(--sp-transition);
}

.sp-persona-filter__btn:hover {
  border-color: var(--sp-border-bright);
  color: var(--sp-text);
}

.sp-persona-filter__btn.is-active {
  border-color: var(--sp-accent);
  background: var(--sp-accent-dim);
  color: var(--sp-accent);
}

.sp-persona-filter__btn[data-persona="junior"].is-active {
  border-color: var(--persona-junior);
  background: var(--persona-junior-bg);
  color: var(--persona-junior);
}

.sp-persona-filter__btn[data-persona="mid"].is-active {
  border-color: var(--persona-mid);
  background: var(--persona-mid-bg);
  color: var(--persona-mid);
}

.sp-persona-filter__btn[data-persona="senior"].is-active {
  border-color: var(--persona-senior);
  background: var(--persona-senior-bg);
  color: var(--persona-senior);
}

/* ── Sections ── */

.sp-section {
  display: flex;
  flex-direction: column;
  margin-bottom: 56px;
}

.sp-section__head {
  margin-bottom: 24px;
}

.sp-section__title {
  margin: 0 0 8px;
  font-family: var(--sp-font-display);
  font-size: clamp(1.25rem, 2.5vw, 1.5rem);
  font-weight: 700;
  color: var(--sp-text);
}

.sp-section__title::before {
  content: "» ";
  color: var(--sp-accent);
  font-family: var(--sp-font-mono);
  font-weight: 500;
}

.sp-section__lede {
  margin: 0;
  color: var(--sp-text-muted);
  max-width: 65ch;
  line-height: 1.7;
}

/* ── Pillars ── */

.sp-pillars {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

@media (min-width: 600px) {
  .sp-pillars {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 900px) {
  .sp-pillars {
    grid-template-columns: repeat(3, 1fr);
  }
}

.sp-pillar {
  padding: 16px;
  border: 1px solid var(--sp-border);
  border-radius: var(--sp-radius-lg);
  background: var(--sp-bg-elevated);
}

.sp-pillar__icon {
  font-size: 22px;
  margin-bottom: 8px;
}

.sp-pillar__title {
  margin: 0 0 6px;
  font-size: 14px;
  font-weight: 600;
  color: var(--sp-text);
}

.sp-pillar__desc {
  margin: 0;
  font-size: 13px;
  color: var(--sp-text-muted);
  line-height: 1.6;
}

/* ── Timeline ── */

.sp-timeline {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
  border-left: 2px solid var(--sp-border);
  margin-left: 8px;
}

.sp-timeline__item {
  position: relative;
  padding: 0 0 24px 24px;
}

.sp-timeline__item:last-child {
  padding-bottom: 0;
}

.sp-timeline__item::before {
  content: "";
  position: absolute;
  left: -7px;
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--sp-bg);
  border: 2px solid var(--sp-accent);
}

.sp-timeline__year {
  display: inline-block;
  margin-bottom: 4px;
  font-family: var(--sp-font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--sp-accent);
}

.sp-timeline__label {
  margin: 0 0 6px;
  font-size: 15px;
  font-weight: 600;
  color: var(--sp-text);
}

.sp-timeline__desc {
  margin: 0;
  font-size: 13px;
  color: var(--sp-text-muted);
  line-height: 1.65;
}

/* ── Persona badges ── */

.sp-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 8px;
  border-radius: 999px;
  font-family: var(--sp-font-mono);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  border: 1px solid transparent;
}

.sp-badge--junior {
  color: var(--persona-junior);
  background: var(--persona-junior-bg);
  border-color: color-mix(in srgb, var(--persona-junior) 35%, transparent);
}

.sp-badge--mid {
  color: var(--persona-mid);
  background: var(--persona-mid-bg);
  border-color: color-mix(in srgb, var(--persona-mid) 35%, transparent);
}

.sp-badge--senior {
  color: var(--persona-senior);
  background: var(--persona-senior-bg);
  border-color: color-mix(in srgb, var(--persona-senior) 35%, transparent);
}

.sp-ver {
  display: inline-flex;
  padding: 2px 7px;
  border-radius: 4px;
  font-family: var(--sp-font-mono);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.03em;
  color: var(--sp-brown);
  background: var(--sp-accent-dim);
  border: 1px solid color-mix(in srgb, var(--sp-accent) 40%, transparent);
  vertical-align: middle;
  margin-left: 6px;
}

/* ── Cards grid ── */

.sp-grid {
  display: grid;
  gap: 16px;
  margin: 0;
  padding: 0;
  list-style: none;
}

@media (min-width: 600px) {
  .sp-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 900px) {
  .sp-grid--3 {
    grid-template-columns: repeat(3, 1fr);
  }
}

.sp-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 20px;
  border: 1px solid var(--sp-border);
  border-radius: var(--sp-radius-lg);
  background: var(--sp-bg-elevated);
  transition: border-color var(--sp-transition), transform var(--sp-transition), box-shadow var(--sp-transition);
}

.sp-card:hover {
  border-color: var(--sp-accent);
  transform: translateY(-2px);
  box-shadow: 0 4px 24px var(--sp-accent-glow);
}

.sp-card__link {
  color: inherit;
  text-decoration: none;
}

.sp-card__link:hover {
  text-decoration: none;
}

.sp-card__icon {
  font-size: 20px;
  color: var(--sp-accent);
  font-family: var(--sp-font-mono);
}

.sp-card__title {
  margin: 0;
  font-size: 16px;
  font-weight: 600;
  color: var(--sp-text);
}

.sp-card__desc {
  margin: 0;
  font-size: 13px;
  color: var(--sp-text-muted);
  line-height: 1.65;
  flex: 1;
}

.sp-card__badges {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: auto;
}

.sp-card--soon {
  opacity: 0.7;
}

.sp-card--soon .sp-card__link {
  pointer-events: none;
  cursor: default;
}

.sp-card--soon:hover {
  transform: none;
  border-color: var(--sp-border);
  box-shadow: none;
}

.sp-card__soon-tag {
  font-family: var(--sp-font-mono);
  font-size: 10px;
  color: var(--sp-accent);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

/* ── Persona intro cards ── */

.sp-personas {
  display: grid;
  gap: 16px;
}

.sp-personas--compact {
  margin-bottom: 24px;
}

@media (min-width: 768px) {
  .sp-personas {
    grid-template-columns: repeat(3, 1fr);
  }
}

.sp-persona {
  padding: 20px;
  border-radius: var(--sp-radius-lg);
  border: 1px solid var(--sp-border);
  background: var(--sp-bg-elevated);
}

.sp-persona__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 12px;
}

.sp-persona__title {
  margin: 0;
  font-size: 14px;
  font-weight: 600;
}

.sp-persona__list {
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 13px;
  color: var(--sp-text-muted);
}

.sp-persona__list li {
  padding: 4px 0;
  padding-left: 14px;
  position: relative;
}

.sp-persona__list li::before {
  content: "›";
  position: absolute;
  left: 0;
  color: var(--sp-accent);
}

.sp-persona__blurb {
  margin: 0;
  font-size: 13px;
  color: var(--sp-text-muted);
  line-height: 1.6;
}

/* ── Callouts ── */

.sp-callout {
  display: flex;
  gap: 12px;
  padding: 14px 16px;
  margin: 20px 0;
  border-radius: var(--sp-radius);
  border: 1px solid var(--sp-border);
  font-size: 14px;
  line-height: 1.65;
}

.sp-callout__label {
  flex-shrink: 0;
  font-family: var(--sp-font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  min-width: 7rem;
}

.sp-callout__body {
  flex: 1;
  min-width: 0;
}

.sp-callout__body p {
  margin: 0;
  color: var(--sp-text-muted);
}

.sp-callout__body p + p {
  margin-top: 8px;
}

.sp-callout__body strong {
  color: var(--sp-text);
}

.sp-callout--pitfall {
  background: var(--sp-red-dim);
  border-color: color-mix(in srgb, var(--sp-red) 35%, transparent);
}

.sp-callout--pitfall .sp-callout__label {
  color: var(--sp-red);
}

.sp-callout--tip {
  background: var(--sp-green-dim);
  border-color: color-mix(in srgb, var(--sp-green) 35%, transparent);
}

.sp-callout--tip .sp-callout__label {
  color: var(--sp-green);
}

.sp-callout--hood {
  background: var(--sp-cyan-dim);
  border-color: color-mix(in srgb, var(--sp-cyan) 35%, transparent);
}

.sp-callout--hood .sp-callout__label {
  color: var(--sp-cyan);
}

.sp-callout--interview {
  background: var(--sp-accent-dim);
  border-color: color-mix(in srgb, var(--sp-accent) 35%, transparent);
}

.sp-callout--interview .sp-callout__label {
  color: var(--sp-accent);
}

.sp-callout--realworld {
  background: var(--sp-purple-dim);
  border-color: color-mix(in srgb, var(--sp-purple) 35%, transparent);
}

.sp-callout--realworld .sp-callout__label {
  color: var(--sp-purple);
}

.sp-callout--version {
  background: var(--sp-grey-dim);
  border-color: color-mix(in srgb, var(--sp-grey) 35%, transparent);
}

.sp-callout--version .sp-callout__label {
  color: var(--sp-grey);
}

.sp-ver {
  display: inline-block;
  padding: 1px 6px;
  border-radius: 4px;
  font-family: var(--sp-font-mono);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--sp-accent);
  background: var(--sp-accent-dim);
  border: 1px solid color-mix(in srgb, var(--sp-accent) 30%, transparent);
  vertical-align: middle;
}

/* ── Code blocks (Prism) ── */

.sp-codeblock {
  position: relative;
  margin: 16px 0;
  border: 1px solid var(--sp-border);
  border-radius: var(--sp-radius);
  overflow: hidden;
  background: #0d1117;
}

.sp-codeblock__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 8px 12px;
  background: var(--sp-bg-panel);
  border-bottom: 1px solid var(--sp-border);
}

.sp-codeblock__lang {
  font-family: var(--sp-font-mono);
  font-size: 11px;
  color: var(--sp-text-dim);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.sp-codeblock__copy {
  appearance: none;
  padding: 4px 10px;
  border: 1px solid var(--sp-border);
  border-radius: 4px;
  background: transparent;
  color: var(--sp-text-muted);
  font-family: var(--sp-font-mono);
  font-size: 11px;
  cursor: pointer;
  transition: color var(--sp-transition), border-color var(--sp-transition);
}

.sp-codeblock__copy:hover {
  border-color: var(--sp-accent);
  color: var(--sp-accent);
}

.sp-codeblock__copy.is-copied {
  border-color: var(--sp-green);
  color: var(--sp-green);
}

.sp-codeblock pre {
  margin: 0;
  padding: 16px;
  overflow-x: auto;
  font-size: 13px;
  line-height: 1.55;
}

.sp-codeblock pre[class*="line-numbers"] {
  padding-left: 3.5em;
}

.sp-codeblock code {
  font-family: var(--sp-font-mono);
}

.sp-inline-code {
  padding: 2px 6px;
  border-radius: 4px;
  font-family: var(--sp-font-mono);
  font-size: 0.9em;
  background: var(--sp-bg-panel);
  border: 1px solid var(--sp-border);
  color: var(--sp-accent);
}

/* Token annotation table */

.sp-token-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
  margin: 16px 0;
}

.sp-token-table th,
.sp-token-table td {
  padding: 10px 12px;
  text-align: left;
  border: 1px solid var(--sp-border);
}

.sp-token-table th {
  background: var(--sp-bg-panel);
  font-family: var(--sp-font-mono);
  font-size: 11px;
  color: var(--sp-text-dim);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.sp-token-table td:first-child {
  font-family: var(--sp-font-mono);
  color: var(--sp-accent);
  white-space: nowrap;
}

/* ── ASCII / diagrams ── */

.sp-ascii {
  margin: 16px 0;
  padding: 16px;
  border: 1px solid var(--sp-border);
  border-radius: var(--sp-radius);
  background: var(--sp-bg-elevated);
  overflow-x: auto;
}

.sp-ascii pre {
  margin: 0;
  font-family: var(--sp-font-mono);
  font-size: 11px;
  line-height: 1.45;
  color: var(--sp-cyan);
}

/* ── Ecosystem map ── */

.sp-eco {
  display: grid;
  gap: 16px;
}

@media (min-width: 768px) {
  .sp-eco {
    grid-template-columns: repeat(2, 1fr);
  }
}

.sp-eco__group {
  padding: 16px;
  border: 1px solid var(--sp-border);
  border-radius: var(--sp-radius-lg);
  background: var(--sp-bg-elevated);
}

.sp-eco__title {
  margin: 0 0 10px;
  font-family: var(--sp-font-mono);
  font-size: 12px;
  font-weight: 600;
  color: var(--sp-accent);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.sp-eco__list {
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 13px;
  color: var(--sp-text-muted);
}

.sp-eco__list li {
  padding: 4px 0;
}

.sp-eco__list strong {
  color: var(--sp-text);
  font-weight: 600;
}

/* ── Compare / trade-off tables ── */

.sp-compare {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
  margin: 20px 0;
}

.sp-compare th,
.sp-compare td {
  padding: 12px 14px;
  text-align: left;
  border: 1px solid var(--sp-border);
  vertical-align: top;
}

.sp-compare thead th {
  background: var(--sp-bg-panel);
  font-family: var(--sp-font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--sp-text-dim);
}

.sp-compare tbody th {
  font-family: var(--sp-font-mono);
  font-size: 12px;
  color: var(--sp-accent);
  background: var(--sp-bg-elevated);
  white-space: nowrap;
}

.sp-compare td {
  color: var(--sp-text-muted);
  line-height: 1.6;
}

/* ── Mermaid diagrams ── */

.sp-mermaid {
  margin: 20px 0;
  padding: 20px;
  border: 1px solid var(--sp-border);
  border-radius: var(--sp-radius-lg);
  background: var(--sp-bg-elevated);
  overflow-x: auto;
}

.sp-mermaid .mermaid {
  display: flex;
  justify-content: center;
}

/* ── Content page layout (sidebar + prose) ── */

.sp-layout {
  display: grid;
  gap: 32px;
}

.sp-layout--doc {
  grid-template-columns: minmax(0, 1fr);
}

@media (min-width: 1024px) {
  .sp-layout--doc {
    grid-template-columns: var(--sp-sidebar-width) minmax(0, 1fr);
    align-items: start;
  }
}

.sp-sidebar {
  display: block;
  position: sticky;
  top: calc(var(--sp-nav-height) + 16px);
  max-height: calc(100vh - var(--sp-nav-height) - 32px);
  overflow-y: auto;
  padding: 16px;
  border: 1px solid var(--sp-border);
  border-radius: var(--sp-radius-lg);
  background: var(--sp-bg-elevated);
}

@media (max-width: 1023px) {
  .sp-layout--doc .sp-sidebar {
    position: static;
    max-height: none;
  }
}

.sp-sidebar__title {
  margin: 0 0 12px;
  font-family: var(--sp-font-mono);
  font-size: 11px;
  font-weight: 600;
  color: var(--sp-text-dim);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.sp-sidebar ol {
  margin: 0;
  padding: 0 0 0 1em;
  font-size: 12px;
  line-height: 1.8;
}

.sp-sidebar a {
  color: var(--sp-text-muted);
  text-decoration: none;
}

.sp-sidebar a:hover {
  color: var(--sp-accent);
}

.sp-page-hero {
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--sp-border);
}

.sp-page-hero__title {
  margin: 0 0 12px;
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
}

.sp-page-hero__title::before {
  content: "class ";
  font-family: var(--sp-font-mono);
  font-size: 0.55em;
  font-weight: 500;
  color: var(--sp-accent);
  vertical-align: baseline;
}

.sp-page-hero__lede {
  margin: 0 0 16px;
  color: var(--sp-text-muted);
  max-width: 65ch;
  line-height: 1.7;
}

.sp-page-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.sp-prose h3 {
  margin: 28px 0 12px;
  font-size: 1.1rem;
  font-weight: 600;
}

.sp-prose p {
  margin: 0 0 16px;
  color: var(--sp-text-muted);
  max-width: 72ch;
}

.sp-prose ul,
.sp-prose ol {
  margin: 0 0 16px;
  padding-left: 1.4em;
  color: var(--sp-text-muted);
  max-width: 72ch;
}

.sp-prose li {
  margin-bottom: 6px;
}

.sp-prose li strong {
  color: var(--sp-text);
}

.sp-prose h3::before {
  content: "// ";
  font-family: var(--sp-font-mono);
  font-size: 0.85em;
  font-weight: 500;
  color: var(--sp-text-dim);
}

.sp-prose h4 {
  margin: 20px 0 10px;
  font-size: 1rem;
  font-weight: 600;
  color: var(--sp-text);
}

.sp-doc {
  min-width: 0;
}

.sp-next-link {
  display: inline-flex;
  align-self: flex-end;
  margin-top: 24px;
  padding: 12px 18px;
  border: 1px solid var(--sp-border);
  border-radius: var(--sp-radius-lg);
  background: var(--sp-bg-elevated);
  color: var(--sp-text);
  font-family: var(--sp-font-mono);
  font-size: 13px;
  text-decoration: none;
  transition: border-color var(--sp-transition);
}

.sp-next-link:hover {
  border-color: var(--sp-accent);
  color: var(--sp-accent);
  text-decoration: none;
}

/* Persona-filtered sections */

[data-personas] {
  transition: opacity 0.2s ease;
}

[data-personas].sp-filter-hidden {
  display: none !important;
}

/* ── Footer (site .footer + hub chrome) ── */

body.spring-core .sp-footer {
  position: relative;
  z-index: 1;
  margin-top: 64px;
  padding: 28px 24px 64px;
  border-top: 1px solid var(--sp-chrome-border, var(--sp-border));
  text-align: center;
  font-size: 11px;
  font-family: var(--sp-font-mono);
  color: var(--sp-chrome-muted, var(--sp-text-muted));
  background: var(--sp-chrome-bg, var(--sp-bg));
}

body.spring-core .sp-footer a {
  color: var(--sp-chrome-accent, var(--sp-cyan));
  border: none;
  text-decoration: none;
}

body.spring-core .sp-footer a:hover {
  color: var(--sp-accent);
  text-decoration: underline;
}

body.spring-core .sp-footer .footer__meta {
  color: var(--sp-text-dim);
}

body.spring-core .sp-breadcrumb {
  font-family: var(--sp-font-mono);
  font-size: 12px;
}

body.spring-core .sp-breadcrumb a {
  color: var(--sp-text-muted);
}

body.spring-core .sp-breadcrumb [aria-current="page"] {
  color: var(--sp-accent);
}

/* Prism theme overrides for Java Core */
body.spring-core pre[class*="language-"] {
  background: #0d1117 !important;
  margin: 0;
}

body.spring-core code[class*="language-"] {
  font-family: var(--sp-font-mono);
  font-size: 13px;
}

html[data-hp-theme="light"] body.spring-core .sp-codeblock {
  background: #f6f8fa;
}

html[data-hp-theme="light"] body.spring-core pre[class*="language-"] {
  background: #f6f8fa !important;
}

/* ── Cheat sheets ── */

.sp-cheatsheet-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 28px;
}

.sp-cheatsheet-nav a {
  padding: 8px 14px;
  border: 1px solid var(--sp-border);
  border-radius: var(--sp-radius, 8px);
  font-size: 12px;
  font-weight: 600;
  text-decoration: none;
  color: var(--sp-text-muted);
  background: var(--sp-bg-elevated, var(--sp-surface));
}

.sp-cheatsheet-nav a:hover {
  border-color: var(--sp-cyan);
  color: var(--sp-cyan);
  text-decoration: none;
}

.sp-cheatsheet {
  margin-bottom: 48px;
  padding: 22px 24px;
  border: 1px solid var(--sp-border);
  border-radius: 12px;
  background: var(--sp-bg-elevated, var(--sp-surface));
  scroll-margin-top: calc(var(--sp-topbar-height, 56px) + 20px);
}

.sp-cheatsheet__head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: 18px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--sp-border);
}

.sp-cheatsheet__title {
  margin: 0;
  font-family: var(--sp-font-display);
  font-size: 1.2rem;
  font-weight: 700;
}

.sp-cheatsheet__lede {
  margin: 6px 0 0;
  font-size: 13px;
  color: var(--sp-text-muted);
  max-width: 55ch;
}

.sp-cheatsheet__copy {
  appearance: none;
  padding: 6px 12px;
  border: 1px solid var(--sp-border);
  border-radius: var(--sp-radius, 8px);
  background: var(--sp-bg);
  color: var(--sp-text-muted);
  font-family: var(--sp-font-mono);
  font-size: 11px;
  cursor: pointer;
}

.sp-cheatsheet__copy:hover,
.sp-cheatsheet__copy.is-copied {
  color: var(--sp-cyan);
  border-color: var(--sp-cyan);
}

.sp-cheatsheet-group {
  margin-bottom: 22px;
}

.sp-cheatsheet-group:last-child {
  margin-bottom: 0;
}

.sp-cheatsheet-group__title {
  margin: 0 0 8px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--sp-amber, #e8b84a);
}

.sp-cheatsheet .sp-token-table {
  font-size: 12px;
}

.sp-cheatsheet .sp-token-table code {
  font-size: 11px;
  white-space: nowrap;
}

.sp-cheatsheet-code {
  margin: 0;
  padding: 14px 16px;
  border: 1px solid var(--sp-border);
  border-radius: 8px;
  background: #0d1117;
  font-family: var(--sp-font-mono);
  font-size: 11.5px;
  line-height: 1.45;
  color: #e6edf3;
  overflow-x: auto;
  white-space: pre;
}

html[data-hp-theme="light"] .sp-cheatsheet-code {
  background: #f6f8fa;
  color: #1a1a2e;
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .sp-card:hover {
    transform: none;
  }
}

@media print {
  body.spring-core::before,
  .sp-topbar,
  .sp-toolbar,
  .sp-sidebar,
  .sp-mobile-nav,
  .sp-cheatsheet-nav,
  .sp-cheatsheet__copy {
    display: none !important;
  }

  .sp-cheatsheet {
    break-inside: avoid;
    border: 1px solid #ccc;
  }

  body.spring-core {
    background: #fff !important;
    color: #000 !important;
  }
}